Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: ATI AT5xxNC Class D Amps

  1. #1
    Join Date
    May 2015
    Posts
    106

    Default ATI AT5xxNC Class D Amps

    Has anyone auditioned (or own) an ATI AT5xx class D amp with Sierra 2's or RAAL towers?
    If so, thoughts?

  2. #2
    Join Date
    Aug 2003
    Location
    Manhattan Beach, California
    Posts
    6,282

    Default Re: ATI AT5xxNC Class D Amps

    I haven’t, but sure would like to. They are supposed to be excellent.
    -curtis

  3. #3
    Join Date
    May 2015
    Posts
    106

    Default Re: ATI AT5xxNC Class D Amps

    thanks, Curtis. I've heard the same. Need to find a dealer nearby to compare with ATI's class AB. The Monoprice Monolith (made by ATI, class AB) also looks to be great, as well

  4. #4
    Join Date
    Nov 2016
    Posts
    26

    Default Re: ATI AT5xxNC Class D Amps

    Quote Originally Posted by racrawford65 View Post
    Has anyone auditioned (or own) an ATI AT5xx class D amp with Sierra 2's or RAAL towers?
    If so, thoughts?
    I have an ATI AT 1802 (AB class) so not a class D. I think it sounds great! never breaks a sweat. I think the only amp I would consider over it is a belles audio. Those are a lot pricier though.

  5. #5

    Default Re: ATI AT5xxNC Class D Amps

    Siegfried Linkwitz has had good experiences with ATI amps for many, many years. I think his work and his web-site are great (I built his Orion speakers, with active crossovers and 10 Emotiva amp channels). On his web-site, he has IM test plots for the AT528NC at 100mW and 1W, both of which look great. Read the page and look for the plots under "Other Power Amplifiers", towards the bottom:
    http://www.linkwitzlab.com/LXmini/Amplifiers.htm#Other

    I have no personal experience of them. I'm Jonesing for a Benchmark AHB2.

    Note: I own and use Sierra 2 and Luna, regularly - their just not my "big" system.

  6. #6
    Join Date
    Dec 2015
    Posts
    22

    Default Re: ATI AT5xxNC Class D Amps

    I thought I read that the switching of the power supplies in class D amps might be audible with sensitive/transparent/hi res tweeters.

    I think the post mentioned that class D were originally invented to achieve high power levels for subs without having to finance the farm, without tripping 15A breakers and without melting down audio audio rack with excessive heat.

    I like the ATI amps a lot but I've been looking at the ATI 1800 and 4000 AB's instead of the AT5xx D's because of the potential switching noise.

    I'll definitely buy the AT5xx amps if my thoughts are incorrect so please do set me straight if I'm off the mark.

  7. #7
    Join Date
    Dec 2015
    Posts
    22

    Default Re: ATI AT5xxNC Class D Amps

    Post #22 in thread "Preamp/Amp Suggestion for Sierra 2" in the loudspeakers forum looks to be a solid discussion on class D amps

    I was wrong, not noise from the power supply, noise from the class D switching itself.

  8. #8

    Default Re: ATI AT5xxNC Class D Amps

    Quote Originally Posted by dfurry View Post
    ... noise from the class D switching itself.
    That doesn't appear to be present in that particular data, and it is a quite sensitive test. On the other hand, Dave did recommend against Class D amps with his products a year ago. Have you tried talking with ATI, directly, for any comments? Perhaps you'll only know by hearing one.

    Meanwhile, I don't see how getting an 1800 or 4000 series amp could be a bad choice. Siegfried sold 1806 amps for his products for many years. How many channels are you looking for, just 2? Lots of choices... If you are looking for "clean" maybe the Benchmark AHB2 would be worth a listen - it is sold on a try at home basis. Whichever way you go, please let everyone know what you think.

  9. #9
    Join Date
    Dec 2015
    Posts
    22

    Default Re: ATI AT5xxNC Class D Amps

    Class D runs at approx 90% efficiency because power semiconductors are switched off when not in use and they are switched on when in use. Early Class D amps used MOSFETs and their switch times are approx 25ns which does cause audible distortion. New power semiconductors such as eGaN FET's switch at about a 5ns rate and this somehow contributes less to distortion. You can read about this here if interested:

    https://www.electronicdesign.com/ana...get-any-better

    ATI has been an innovative quality amp designer for years and it just seems they wouldn't have GA'd the new amps without them working well well with all drivers, regardless of sensitivity, but that's just an opinion.

    These new amps are cheaper, they consume less power plus they're smaller and lighter:

    Two to four channel models: 17"W X 5 3/4"H X 10 5/8"D
    Five to eight channel models: 17"W X 5 3/4"H x 15 1/2"D
    39 to 62 1/2 lbs

    So tempting ......

  10. #10

    Default Re: ATI AT5xxNC Class D Amps

    All true. And the eGaN FET looks to improve performance in designs that use it. While that is nice, technically, you are interested in the highest audio performance (I think), and need to know about specific amp implementations, not just specs of a single electronic component.

    I assume you have already read these:
    https://www.stereophile.com/content/...nel-amplifiers
    https://www.soundandvision.com/conte...lifiers-review

    The ATI design claims to use Hypex NCore output modules, which are in high end amps from several manufacturers. They are relatively new, and well regarded. Since the technology seems to interest you, you might want to read more about them.

    But for many of us, two amps often sound different when we do not see why in the available measurements. In this case, I can't really see any 'switching noise' in the ATI amp and I would not expect to hear any. Period. But, depending on your own taste, associated equipment, etc, you still might not like how it sounds. Or, you might be very satisfied on every level.

    Which brings you to your original question, has anyone used them on these RAAL equipped speakers?
    Last edited by jimb; 09-02-2018 at 11:14 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •